Test Subject by ImoutoCommissions

Lettuce had always been a shy girl, ever since her childhood, and 
because of that, she had gotten fairly good at holding back when her 
bladder got full. She found that simply holding it was often much easier 
for her than getting up the nerve to excuse herself, and that finding 
the words to say what she needed was much too embarrassing for her. But 
after she became a Mew, she discovered that her water powers actually 
benefited her a lot on that front, and that if she focused her powers on 
her bladder, then she could hold back for even longer than before. It 
seemed that no matter how bad things got, she was able to endure with 
her powers.

One day at the cafe, when they were incredibly busy, she was using that 
to her advantage. Her bladder was so uncomfortably full that she had to 
do everything she could to keep working at the pace she needed to, and 
when it was time for her to go home, she had to resist the urge to sigh 
in relief. When she went to get changed out of her uniform, she would be 
able to go, and the problem would be solved.

Unfortunately, just as she was getting ready to do this, Ryou called a 
meeting in the back, and looked incredibly serious as he did so. Lettuce 
reluctantly followed the other girls, where he grimly informed them that 
the presence of a chimera anima had been detected, and that they would 
have to transform right away to pursue it. Though Lettuce really needed 
to visit the bathroom before she left, she was much too shy to say so, 
and did not do it, hoping that her bladder would not fail her before the 
battle was over and she could return home.

As soon as they happened upon the creature, they began to fight with all 
their strength...or, at least, the other girls did. Lettuce had to focus 
too much on her own situation, and the water of her attacks did not help 
her hold on in the slightest. In the end, she found herself hanging back 
more often than not, because getting directly involved would only hinder 
her teammates further and make things harder on herself. It was because 
of this that she was such an easy target.

Before she knew what was happening, Pai had appeared behind her and 
grabbed her, and she was gone before her teammates noticed and before 
she could scream for help. The next thing she knew, he had teleported 
her to a lab and was strapping her down to an examination table, and 
though she struggled, she could not break the bonds that held her down.

"I've captured you because I feel that studying your biology will better 
help us understand how to defeat you," he said by way of explanation, 
before preparing himself to do some tests. She was so close to her limit 
that she could not afford to use her powers for anything else but 
holding it, which meant that she could not use her powers to escape.

She knew that she would not be able to hold it if she tried to wait this 
out, but her shyness would not allow her to give in, and she kept 
fighting to hold on, even knowing how useless it was. Struggling against 
time, she squirmed a bit under her bonds, and if Pai noticed, he 
probably thought that it was just another pathetic attempt at escaping 
and did not comment on it.

Her bladder throbbed, begging for relief that she would not grant it, 
and Pai got a needle to take a blood sample from her. It took all she 
had not to lose control when the prick of the needle made her jolt a 
bit, and she just barely managed to keep the flood at bay while he put 
his sample away for safekeeping and took something else to scrape at the 
palm of her hand for a skin sample. This also caused her enough pain 
that her bladder nearly gave out on her, and Lettuce grit her teeth, 
willing to do anything keep from wetting herself, even knowing that it 
was inevitable.

Lettuce squeezed her thighs together, trying to keep her breathing even 
and trying to keep from crying even though tears threatened to fall. Her 
control was wearing thin, and there was nothing she would be able to do 
to convince Pai to let her go for even a second, even if she weren't too 
shy to ask him in the first place. All she could do was lay there and 
fight against something that she knew she could not avoid in the long 
run.

When he began a basic physical examination of her, she knew that she was 
doomed, and she bit her lip as he ran his hands along her. His touches 
were not intimate in nature and were purely for the sake of his studies, 
but it was still more than she was used to from somebody else and it 
caused her resolve to weaken further. Using all of her willpower, she 
refused to wet herself yet, especially not when he was so close like 
this, but then his hand rested on her lower abdomen, and though he was 
not doing it intentionally, Pai applied just enough pressure to push her 
over the edge.

The slight amount of pressure was too much for her bladder to handle, 
and she let out a pathetic cry as she felt her control slipping once and 
for all, and then no force on earth could stop the sudden rush of urine. 
Her bladder had been so full that this went on for quite a while, and 
Pai just watched curiously as she soaked through her costume and it 
began to puddle on the table beneath her.

"Stop staring at me!" she shouted, tears finally falling and her face 
bright red in humiliation. Surprised by her outburst, he actually 
complied, giving her the slightest bit of privacy as her bladder emptied 
itself. The puddle extended over the edge of the table, pouring off onto 
the floor on both sides until it formed another large puddle beneath the 
table, and when Pai looked back, he was surprised at how much liquid she 
had been able to contain. He had a moment to make a mental note of that 
for future study before Lettuce's anger and humiliation overtook her.

Without her powers being used for anything else, she was able to summon 
a large torrent of water into his lab, which shorted out the electricity 
and allowed her freedom from her bonds. Not only that, but any traces of 
her accident were washed away, and Pai had no choice but to flee, 
teleporting and leaving her by herself.

She gave a small sigh of relief to know that she had made it out of that 
alive. It had been embarrassing, but she had survived it, and now all 
there was left to do was try to find her way home from wherever Pai had 
taken her.